Previous internal combustion engine have attempted to reduce knock by promoting flow mixing through swirl and tumble flow patterns generated in the combustion chamber. Additionally, certain engine designs have incorporated vertically aligned valves to increase the engine's compression ratio. Vertically aligning the valves, however, decreases the amount of tumble in the combustion chamber due to the previous intake conduit designs matched with the vertical valves. Therefore, in previous engine designs a tradeoff may be made between increased compression ratio and tumble generation.
To resolve at least some of the abovementioned problems, an engine system is provided that comprises an inlet valve and an outlet valve aligned along a longitudinal axis of a cylinder head. A central axis of each of the inlet and outlet valves is arranged parallel to a central axis of a combustion chamber. The engine system further comprises an intake line adjoining an inlet opening of the combustion chamber and extending axially above an end of an inlet valve stem with regard to a central axis of the inlet valve. By arranging the intake line in this manner, a flow pattern in the combustion chamber is generated that decreases the likelihood knock. One of the flow characteristics enabling the decrease in knock tendency is an increase in tumble flow. The decrease in knock tendency allows the compression ratio of the engine to be increased, if desired. Therefore, by aligning the inlet and outlet valves in parallel with the combustion chamber's central axis, the compression ratio of the combustion chamber is increased. In this way, the aforementioned engine system achieves the synergistic benefits of decreasing the likelihood of knock and increasing compression ratio of the engine. As result, engine efficiency is increased.
In one example, the engine system may further comprise a valve drive actuating the inlet valve, where the valve drive is positioned on a first lateral side of the cylinder head and the exhaust-gas line is positioned on a second lateral side of the cylinder head spaced away from the first lateral side. In this way, the engine system may efficiently package the valve drive and the exhaust-gas line without augmenting the vertical alignment of the intake line.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
FIGS. 1-3C are shown approximately to scale. However, other relative dimensions may be used, in other embodiments.